1. Field of the Invention
The present invention relates to an apparatus for handling viscous materials, to methods of making such apparatus, to compositions useful for making such apparatus, and to methods of making such compositions. In another aspect, the present invention relates to plastic containers having inside surface properties that result in enhanced product drainage from the container and the reduction of product residual levels, to methods of making such containers, and to plastic compositions useful in making such containers.
2. Description of the Related Art
Many liquid consumer products are provided in jars, bottles, tubes, or other containers, from which they are dispensed. Very commonly, the consumer pours, pumps, sprays, squeezes, or shakes the product out of the container. As most consumers have encountered, certain viscous products have a tendency to stick to or hang-up on the inside surface of the container, and there is always a residual amount of the product which cannot be evacuated from the container by simply pouring, pumping, squeezing, or shaking. With certain container geometries which do not permit suitable access to the inside of the container, this residual amount is inevitably discarded with the used container.
Polyethylene has long been a favored material for use in making containers for a wide range of consumer products. It is easily and economically formed into a multitude of geometric shapes to fulfill any engineering or marketing requirements. Its physical properties provide suitable strength and toughness to withstand shipping, handling, storage, and the occasional drop, and yet still allow for squeezability by consumers. Finally, the cost of the material itself is not an undue economic burden, which is important for a disposable container.
Common container materials (e.g., polyethylene) suffer greatly from the problem of product residue. Specifically, high product residual levels can be a problem in polyethylene containers, especially when the products contained are viscous materials, e.g., oil-in-water emulsions, water-in-oil emulsions, polymeric gels, foams, surfactant mixtures, dispersions, colloidal dispersions, suspensions, polymer solutions, polymer melts, and food products such as condiments, sauces, pastes, syrup and the like.
Typically, such viscous materials can be attracted to the interior surface of HDPE containers, with this attraction leading to a residual layer of product remaining on the interior container walls. In some instances, this residual amount may be on the order of 10 to 25 or more weight percent.
A similar type of product residual problem can occur in any application in which viscous materials are contacting nozzles, tubing, hoses, sprayers, funnels, piping, trays, troughs, liners, ductwork, channels, tanks, utensils, scoops, cups, pots, pitchers, brushes, pistons, impellers, stirrers, films, laminates, pouches, bags and sachets, pumps, tubes, pipets and jars and the like.
Prior art solutions to these type of product residual problems have suggested additives, blends or coatings to render the surface repellant of the viscous material.
For example, U.S. Pat. No. 5,560,544, issued October 1, to Merritt et al., discloses the problem of product accumulation on the walls or passage or the sides of an atomizer nozzle orifice. As a solution, Merritt et al. disclose a reduced wettability composition for the nozzle including a base component and a wettability-reducing component for reducing the wettability of the base material with the fluid product. Merritt et al. teaches that the "reduced wettability attribute" ensures that the product will tend to "bead up" on and be repelled by the surfaces of the nozzle rather than wetting or coating the surfaces.
Derwent WPI Acc No.: 96-018445/02 discloses a releasing compound for use in the packaging of sticky or viscous products, where the inner layer of packaging is prepared by compounding polyolefins containing reactive groups (alkylozysilane etc.) with silicone oil, which also contains reactive groups (silanol etc.).
Japanese patents JP02008047 and JP93077510 disclose a plastic container useful for viscous foodstuffs containing fat and oil having a viscosity above 30,000 cp. The portion of the container contacting with the foods stuffs is made of a hydrophobic plastic blended with 400-50,000 ppm of a blended-resin.
Nippon Nohyaku Co., Ltd., Publication no. 08113244 and application date May 07, 1996, discloses a bottle composed primarily of synthetic resin coated on the interior face with a silicone oil to prevent viscous or adhesive liquid from sticking to its inner surface.
However, in spite of the prior art teachings, there is a need in the art for improved product containers, for compositions for making such containers, and for methods of making such containers.
There is another need in the art for product containers having reduced product residue, for compositions for making such containers, and for methods of making such containers.
There is even another need in the art for improved product containers having inside surface properties that result in enhanced product drainage from the container and the reduction of product residual levels, for compositions for making such containers, and for methods of making such containers.
There is still another need in the art for nozzles, tubing, hoses, sprayers, funnels, piping, trays, troughs, liners, ductwork, channels, tanks, utensils, scoops, cups, pots, pitchers, brushes, pistons, impellers, stirrers, films, laminates, pouches, bags, and sachets, pumps, tubes, pipets and jars and the like, having reduced product residue, for compositions for making such, and for methods of making such.
These and other needs in the art will become apparent to those of skill in the art upon review of this specification, including its drawings and claims.